Extreme to exceptional drought conditions across Oklahoma dried up much of the hay and forage crops needed to keep cattle herds healthy through the winter.
Not only are food sources scarce, experts say, the forage available could be toxic to livestock. The combination of drought and unseasonably hot weather boosts nitrate levels in sorghum, corn and other forage crops, and can be deadly.
Andy Qualls, Muskogee County Conservation District technician, said rapidly developing drought conditions causes a rapid uptake of nitrogen. When temperatures exceed 95 degrees, plant growth is stunted. As a result, stored nitrogen becomes trapped in the plants.
“The nitrate problem is particularly bad this year,” Qualls says. “Livestock is especially susceptible, and this can cause death.”
Ranchers who plan to use forage crops that accumulate nitrates during hot, dry seasons, Qualls said, are encouraged to have the forage tested. The Oklahoma State University Extension Service provides that service.
Qualls says nitrogen levels can vary widely from one end of the field to another. As a result, he recommends testing samples from every fourth or fifth bale for locally produced forage.